1. Field of the Invention
The present invention relates to folding doors used, for example, as the door of a lavatory in an airplane.
2. Description of the Prior Art
Folding doors do not use up as much space, when opening and closing, as compared to normal board-type doors accordingly, they are normally utilized in the lavatory of airplanes, telephone boxes, bath units of houses, and the like.
FIG. 14 is a view showing folding doors used in lavatory units of airplanes.
The folding doors 1 comprise of a first door panel 2 and a second door panel 3, and the first door panel 2 and the second door panel 3 is connected by a hinge 4.
FIG. 15 is a cross sectional view showing the hinge 4. The hinge includes having a structure hinge members 4A, 4B, forming a gear portion, set on the end portions of the door panels 2, 3, and both hinge members are held by a cover member 4D.
By the engagement of the gear portion of hinge members 4A, 4B, the two door panels 2, 3 fold smoothly, and the sealing ability is improved because the hinge members are held by the cover 4D.
A coil spring 5 (FIG. 16) is set in the hinge portion, and forces the door panels 2, 3 to be parallel, i.e. forming a plane surface (to be closed) basically.
FIG. 16 shows the detail of the coil spring 5. As noted, the coil spring 5 is positioned between the first door panel 2 and the second door panel 3 and it forces the folded panels 2, 3 in the direction to return to a position forming a plane surface.
A door locking device 8 (FIG. 14) is set on the second door panel 3. A pin 6 is mounted on each of the upper and lower end portions of the first door panel 2, and the pins support the folding doors 1 rotatably on the side of the wall of the lavatory unit.
A guiding device 7 (FIGS. 19 and 17) is set on the upper portion of the second door panel 3, and it enables the second door panel 3 to open and close along the door opening portion of the lavatory unit.
FIG. 17 shows the details of the guiding device 7. The guiding device 7 set on the upper portion of the second door panel 3 includes a slider 7A and a shaft 7B which supports the slider VA. The slider 7A, for example, has a quadrilateral plane form, and fits in the guide rail 9 formed on the door opening portion.
When the second door panel 3 opens or closes, the slider 7A guides the second door panel smoothly by sliding through the guide rail 9.
When the plane form of the slider 7A is a quadrilateral, the slider 7A moves along a straight line and the door panel 3 moves in a gyrating manner so the slider 7A rotates against the shaft 7B.